JP2007001039A - Rubber continuous kneading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber continuous kneading method capable of reducing initial flow loss at the start time of kneading without lowering treatment efficiency. <P>SOLUTION: At the start of kneading, a predetermined amount of a pre-supply rubber, of which the particle size is larger than that of a powdery raw material rubber, is first supplied to a continuous kneader 1 and the powdery raw material rubber is subsequently supplied continuously to be sent into the kneading zone 8a of the continuous kneader 1 in a state that the powdery raw material rubber is filled with the pre-supply rubber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rubber continuous kneading method capable of reducing initial flow loss at the start of kneading.

  Continuous kneading of rubber is obtained by non-pro rubber kneading in which additives (excluding vulcanizing agents and vulcanization accelerators) such as reinforcing agents, fillers and plasticizers are added to rubber and kneaded, and non-pro rubber kneading. It is roughly classified into final rubber kneading in which vulcanized chemicals (vulcanizing agent and vulcanization accelerator) are added to kneaded rubber (non-pro rubber) and kneaded. The rubber (final rubber) obtained by the final rubber kneading is extruded with a predetermined cross-sectional shape by, for example, an extruder, then cut at a predetermined length, and vulcanized. In the case of a foam molded product such as a weather strip, a foaming agent is added together with the vulcanizing chemical.

  Conventionally, as the raw rubber for the above non-pro rubber kneading or final rubber kneading, those formed into a ribbon shape or a sheet shape are used, and they are cut to a predetermined length or continuously through an extruder. (For example, refer to Patent Document 1 below). On the other hand, as the raw material rubber, there may be used a powder molded by pulverization or pulverization or the like, and according to such a form, the additives and the like are more uniform than the raw material rubber in the form of a ribbon or sheet. There is an advantage that dispersion can be easily obtained. Further, since the additives and the like can be supplied from the same supply port as that of the raw rubber, the mixing action can be obtained at an early stage, and the equipment can be made compact.

  However, when powdered raw rubber is supplied to a continuous kneader, there is a problem that at the start of kneading, the initial flow of raw rubber is discharged in the form at the time of supply, or discharged in an insufficiently kneaded state. there were. In some cases, the rubber discharged in this way can be supplied again to the continuous kneader and kneaded again. However, the final rubber kneading performed by adding a vulcanizing chemical reinstates the heat history because it changes. It could not be used, resulting in a loss (initial loss), leading to an increase in cost and a decrease in productivity.

The present inventors diligently researched this initial flow loss and came to pay attention to the particle size of the raw rubber. That is, since the particle size of the raw rubber was smaller than the gap formed between the screw, barrel, shear pin, etc. of the continuous kneader, it was considered that the raw rubber was not properly kneaded in the kneading zone of the continuous kneader. However, when the particle size of the raw rubber is made relatively large, the bulk specific gravity is reduced and the resistance to the barrel in the transfer zone is increased. There was a problem that efficiency decreased.
JP 2000-43032 A

  This invention is made | formed in view of the said situation, The objective is to provide the rubber | gum continuous kneading method which can reduce the initial loss at the time of kneading | mixing, without reducing processing efficiency.

  The above object can be achieved by the present invention as described below. That is, the rubber continuous kneading method according to the present invention includes a supply step of continuously supplying powdery raw rubber to a continuous kneader, and a kneading step of kneading the raw rubber in a kneading zone of the continuous kneader. The rubber continuous kneading method comprises a pre-feeding step of supplying a predetermined amount of pre-feed rubber having a particle size larger than that of the raw rubber to the continuous kneader before starting the kneading when the kneading is started. In the process, the raw rubber is fed into the kneading zone filled with the pre-supplied rubber and kneaded.

  According to the rubber continuous kneading method according to the present invention, when the kneading is started, the pre-supplied rubber reaches the kneading zone of the continuous kneader first by supplying a predetermined amount of the pre-supplied rubber prior to the raw rubber. Subsequently, the raw rubber arrives. The pre-supplied rubber has a larger particle size than the raw rubber and is filled relatively easily when it reaches the kneading zone. The raw rubber is fed into the kneading zone filled with the pre-supplied rubber and kneaded. . For this reason, the raw rubber is appropriately plasticized in the kneading zone, and is not discharged from the continuous kneader as it is supplied or discharged in an insufficiently kneaded state, thereby reducing the initial flow loss. be able to. Further, the present invention supplies a predetermined amount of pre-supplied rubber only at the start of kneading, and does not increase the particle size of the continuously supplied raw rubber. There is no reduction in efficiency.

  The supply amount of the pre-feed rubber in the pre-feed step may be an amount that can be filled in the kneading zone that is reached first at the start of kneading. Such a supply amount can be obtained by calculation based on the volume of the kneading zone or the like, but can also be obtained experimentally. The raw rubber is a variety of rubber materials typified by natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), etc. in the case of non-pro rubber kneading, and in the case of final rubber kneading, the non-pro rubber kneading. The resulting non-vulcanizable rubber composition (non-pro rubber) is obtained.

  In the above, the continuous kneader includes a cylindrical barrel having an inner diameter of D1 and a screw rotating around the axis in the barrel and having an axis diameter of D2, and the particle size d of the pre-feed rubber is Those satisfying (D1-D2) /2×0.5≦d are preferable.

  According to the above configuration, it becomes difficult for the pre-supplied rubber to pass between the screw of the continuous kneading machine and the inner surface of the barrel, and when the rubber reaches the kneading zone at the start of kneading, the pre-supplied rubber is filled more easily. It can be effectively reduced. Here, the particle diameter d of the pre-supplied rubber is obtained by sieving a predetermined amount (for example, 1 kg) using a JISZ8801 sieve, and measuring the weight remaining on each sieve. The average particle size obtained by the sum is taken. In addition, since the pre-feed rubber obtained by pulverization includes small-diameter rubber that does not satisfy the above formula, it is preferable to use a rubber that has been previously removed with a sieve or the like.

  In the above, it is preferable that the pre-supplied rubber is in a powder form and includes an anti-adhesive removing step for removing the anti-adhesive applied to the pre-supplied rubber before the pre-feeding step.

  Usually, a powdery rubber obtained by pellet molding or pulverization is coated with an adhesion preventing agent for preventing aggregation. However, if an anti-adhesive agent is applied to the powdered pre-supplied rubber, the friction with the barrel or the like tends to be reduced due to this, and the residence time in the kneading zone tends to be shortened. It may be difficult to fill in the kneading zone. Therefore, by providing a step of removing the anti-adhesive agent before the pre-feeding step, it is possible to avoid a decrease in friction between the pre-feed rubber and the barrel, etc., and the state where the pre-feed rubber is filled in the kneading zone is appropriate. Is obtained. As a result, the raw rubber is reliably kneaded in the kneading zone, and the initial flow loss can be suitably reduced.

  In the above, it is preferable to include at least one of a rubber preheating step for preheating the pre-feed rubber before the pre-feed step and a kneading zone pre-heating step for preheating the kneading zone until the pre-feed rubber is filled. .

  According to the said structure, the adhesiveness of the pre supply rubber | gum in a kneading zone is improved, and the state with which the pre supply rubber | gum was filled in the kneading zone is obtained effectively. As a result, the raw rubber is reliably kneaded in the kneading zone, and the initial flow loss can be suitably reduced. When the continuous kneader has a plurality of kneading zones, it is not necessary to preheat all of them, and at least the kneading zone where the pre-supplied rubber reaches first may be preheated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, although the example of final rubber kneading is shown in the following embodiment, the present invention can be applied to both non-pro rubber kneading and final rubber kneading.

<First Embodiment>
FIG. 1 is a schematic configuration diagram of a rubber continuous kneading facility. 2 is a cross-sectional view taken along line AA in FIG. The rubber continuous kneading equipment includes a continuous kneader 1, a rubber supply device 20 for quantitatively supplying raw rubber to the continuous kneader 1, and a chemical supply device for quantitatively supplying vulcanized chemicals to the continuous kneader 1. 30.

  The continuous kneader 1 includes a screw 10 for continuously kneading rubber and a cylindrical barrel 2 in which the screw 10 is built. The screw 10 is formed by projecting a fin-like screw blade 12 made of a thin plate on the surface of the mandrel 11, and is supported in a cantilever manner by a screw driving device 13 provided at an end of the barrel 2. . The screw 10 is driven by a screw driving device 13 and is configured to be capable of reciprocating a predetermined distance in the axial direction while rotating at a predetermined speed around the axis.

  In the screw 10, a kneading segment 14 having a large kneading action and a conveying segment 15 having a large carrying action are alternately arranged in the axial direction, the former constituting the kneading zone 8 of the continuous kneader, and the latter being Conveying zone 9 of the continuous kneader is configured. The length and number of the kneading zone 8 and the transport zone 9 can be changed as appropriate according to the purpose. In the kneading segment 14 of the present embodiment, as shown in FIG. 2, three notches are formed at equal intervals between one pitch of the screw blades 12, and the notches of adjacent pitches have the same phase. It is arranged. On the other hand, the screw segment 12 is formed in the conveying segment 15 at a pitch larger than that of the kneading segment 14, and one notch (not shown) is formed between one pitch.

  The barrel 2 is formed by connecting a plurality of cylindrical blocks in the longitudinal direction, a screw drive device 13 is provided at one end, and a discharge port 3 is formed at the other end. The discharge port 3 is provided with a die (not shown) for extruding rubber with a predetermined cross-sectional shape. A supply port 4 is provided on the upper surface of the barrel 2 on the screw drive device 13 side, and a cylindrical shooter 5 constituting a supply path for raw rubber and vulcanized chemicals is connected thereto. A funnel-shaped hopper 6 is connected to the upper end of the shuter 5, and raw rubber and vulcanized chemicals are supplied from the same supply port 4 as will be described later.

  In the present embodiment, a transport segment 15 is disposed immediately below the supply port 4. A plurality of shear pins 7 project from the inner surface of the barrel 2 so as to enter the notch of the screw blade 12 as shown in FIG. 2 so that the kneading action in the kneading segment 14 can be enhanced. It is configured. Further, the shear pin 7 also enters the notch of the screw blade 12 of the conveying segment 15 and has an effect of preventing the backflow of rubber when the screw 10 is retracted. Such a continuous kneader is known and, for example, “BUSS Kneader” manufactured by Coperion Co., Ltd. can be mentioned as a suitable apparatus.

  The rubber supply device 20 and the chemical supply device 30 are disposed above the shooter 5. The rubber supply device 20 is constituted by a weight type belt feeder having a hopper 21 that stores powdered raw rubber and a belt conveyor 22 that transports the raw rubber discharged from the lower portion of the hopper 21 in the horizontal direction. A load cell for detecting a passing flow rate (weight) is provided under the belt of the belt conveyor 22, and the conveyance speed is adjusted so that the raw rubber is quantitatively charged into the hopper 6. Further, the chemical supply device 30 is constituted by a weight type screw feeder having a hopper 31 for storing a vulcanized chemical and a single or biaxial screw 32 connected to the lower portion of the hopper 31. The cutting amount of the vulcanizing chemical is determined based on the weight of the entire apparatus, and the rotational speed of the screw 32 is adjusted so that the vulcanizing chemical is quantitatively charged into the hopper 6. Although only one chemical supply device 30 is shown in FIG. 1, actually, each of the vulcanizing agent and the vulcanization accelerator is provided.

  The rubber continuous kneading equipment includes a control device (not shown) for controlling the supply amount and kneading amount of raw rubber and vulcanizing chemicals. The control device controls the continuous kneader 1, the rubber supply device 20, and the chemical supply device 30 so that the mixing ratio of the raw rubber and the vulcanized chemical is constant.

  Next, final rubber kneading using the rubber continuous kneading equipment will be described. First, the raw rubber is supplied to the hopper 21 of the rubber supply device 20 and the vulcanized chemical is supplied to the hopper 31 of the chemical supply device 30. This embodiment is an example of final rubber kneading, and as a raw rubber, a non-vulcanizable rubber composition (non-pro rubber) obtained by adding and kneading additives such as reinforcing agents, fillers, and plasticizers to rubber. Is used.

  The raw rubber is a powdered rubber obtained by pellet molding or pulverization, and the shape and dimensions thereof are not particularly limited. However, the particle diameter is generally smaller than (barrel inner diameter D1—screw shaft diameter (mandrel diameter) D2) / 2, and if it exceeds this, the bulk specific gravity becomes smaller and the supply port becomes smaller. 4 and the resistance to the inner surface of the barrel 2 in the transport zone 9 increases before plasticization, so that the transport capability of the continuous kneader 1 tends to decrease. The raw rubber is coated with an adhesion preventing agent for preventing aggregation. As the anti-adhesive agent, organic or inorganic non-aggregating powders such as calcium carbonate, magnesium carbonate, clay, talc and silica can be used.

  The above raw rubber and vulcanized chemicals are respectively quantitatively introduced into the hopper 6 so as to have a predetermined mixing ratio, and are supplied to the continuous kneader 1 via the shooter 5 (corresponding to the supply step). . The raw rubber is conveyed toward the right side of FIG. 1 by the rotation of the screw 10, and the screw 10 reciprocates a predetermined distance in the axial direction in synchronization with the rotation, whereby the screw blade 12 and the barrel 2 are moved in the kneading zone 8. The inner surface is cut by the shear pin 7 and subjected to a shearing action, so that kneading is effectively performed. The raw rubber that has reached the discharge port 3 via each kneading zone 8 is discharged in a state of being kneaded with a vulcanizing chemical.

  In the present invention, in the present invention, when starting kneading, a predetermined amount of pre-supplied rubber having a particle size larger than that of the raw rubber is supplied to the continuous kneader 1 prior to the supply of the raw rubber (corresponding to the pre-feeding step). .), The pre-supplied rubber is followed by raw rubber. The pre-supplied rubber can be easily supplied by placing a predetermined amount of pre-supplied rubber in the vicinity of the discharge side on the belt conveyor 22 in advance. I do not care.

  By supplying the pre-supplied rubber prior to the raw rubber, the pre-supplied rubber first reaches the kneading zone 8a located at the most upstream, followed by the raw rubber. The pre-feed rubber having a particle size larger than that of the raw rubber is filled at the same time as plasticization when reaching the kneading zone 8a, and the raw rubber is fed into the kneading zone 8a filled with the pre-feed rubber and kneaded. (This corresponds to the kneading step). The state of filling may be a state in which rubber is filled to the same extent as a kneading zone in a state where continuous rubber kneading is regularly performed during normal operation. The raw rubber is appropriately plasticized in the kneading zone 8a, and the initial flow loss can be reduced without being discharged in the form of a powder or being discharged in an insufficiently kneaded state.

  The form of the pre-supplied rubber is not particularly limited and may be, for example, a short ribbon shape, but the powder form obtained by pellet molding or pulverization may disperse or treat vulcanized chemicals. It is preferable from the viewpoint of efficiency. In such a case, the particle diameter d of the pre-feed rubber preferably satisfies (D1-D2) /2×0.5≦d≦ (D1-D2) / 2. When d <(D1-D2) /2×0.5, the pre-supplied rubber easily passes between the screw 10 and the inner surface of the barrel 2, and the above-described effect by supplying the pre-supplied rubber is small. Tend to be. On the other hand, if d> (D1-D2) / 2, the efficiency of entering the supply port 4 may be reduced.

  The pre-supplied rubber is preferably made of rubber having the same composition as the raw rubber, so that the initial flow made of the pre-supplied rubber can be adopted as a product, and the occurrence of initial flow loss can be made zero. In such a case, the vulcanized chemicals are supplied together with the pre-supplied rubber. On the other hand, the pre-feed rubber may be made of rubber having a different composition from the raw rubber. In such a case, a very small initial flow loss made of pre-supplied rubber is generated, but the initial flow loss of the raw rubber is reduced.

  The pre-supplied rubber having the same composition as the raw rubber is obtained by molding the raw rubber (non-pro rubber in this embodiment) into the above-mentioned size. Also good. The wake loss is one that remains in the die or is discharged in an insufficiently kneaded state at the end of kneading. Such wake loss is caused by a low upstream rubber filling rate, and there is no problem in terms of blending. Since the present embodiment is final rubber kneading, the wake loss is targeted for non-pro rubber kneading that is the previous step.

Second Embodiment
Hereinafter, the second embodiment of the present invention will be described focusing on the differences while omitting the description of the configuration common to the first embodiment.

  The rubber continuous kneading equipment shown in FIG. 3 is configured in substantially the same way as the rubber continuous kneading equipment shown in FIG. 1, but a supply port 16 is provided on the upper surface of the barrel 2 of the continuous kneader 1. The difference is that the chemical supply device 30 is disposed above the shooter 5 connected to the supply port 16. The portions immediately below the supply port 4 and the supply port 16 are transport zones 9 each composed of a transport segment 15, and a kneading zone 8 composed of a kneading segment 14 is disposed therebetween. That is, in the present embodiment, the raw rubber and the vulcanized chemical are supplied from different supply ports, and after the raw rubber is plasticized once, kneading with the vulcanized chemical is performed.

  The pre-supplied rubber used in the present embodiment is in a powder form, and an adhesion preventing agent for preventing aggregation is applied at the time of molding. The pre-supplied rubber is supplied to the continuous kneader 1 prior to the raw rubber in the same manner as in the first embodiment, but in this embodiment, the anti-adhesive agent applied to the pre-supplied rubber is removed before that. (Corresponds to the anti-adhesive agent removal step). Thereby, the fall of friction with pre supply rubber, barrel 2, etc. can be avoided, and the state where pre supply rubber was filled into kneading zone 8a is obtained appropriately. As a result, the raw rubber is reliably kneaded in the kneading zone 8a, and the initial flow loss can be suitably reduced.

  The method for removing the anti-adhesive agent is not particularly limited, and may be manual wiping or washing with water. When the anti-adhesive agent is made of calcium carbonate, the pre-supplied rubber may be immersed in a dilute acetic acid solution and stirred to melt and remove the anti-adhesive agent. In this embodiment, since the vulcanized chemical is supplied to the conveyance zone 9 adjacent to the downstream side of the kneading zone 8a where the pre-supplied rubber first arrives, the pre-supplied rubber and the barrel 2 and the like are used by the vulcanized chemical. Friction with is never reduced.

  Further, in the present embodiment, before supplying the pre-supplied rubber to the continuous kneader 1, a step of preheating the pre-supplied rubber to a predetermined temperature using a heating means such as an oven (corresponding to the rubber preheating step). Prepare. Thereby, the adhesiveness of the pre-supplied rubber is enhanced, and a state in which the pre-supplied rubber is filled in the kneading zone 8a is effectively obtained. As a result, the raw rubber is reliably kneaded in the kneading zone 8a, and the initial flow loss can be reduced. The preheating temperature should just be the temperature which exhibits the adhesiveness advantageous for the pre-supply rubber | gum being filled into the kneading zone 8a, for example, the temperature of about 70-100 degreeC is illustrated.

<Another embodiment>
(1) This invention is not limited to a specific thing about the mixing | blending of raw rubber and pre-feed rubber. Moreover, although the example in final rubber kneading was shown in the above-mentioned embodiment, this invention can be used also in the case of non-pro rubber kneading.

  (2) In the second embodiment described above, an example in which the pre-feed rubber is preheated before being supplied to the continuous kneader has been shown. However, in the present invention, instead of or in addition to this, the kneading zone 8a is pre-feed rubber. May be provided with a step of preheating until it is filled (corresponding to the kneading zone preheating step). Even with such a configuration, the above-described effects can be effectively achieved. The preheating of the kneading zone 8a is performed at a temperature, for example, about 70 to 100 ° C., that exhibits advantageous adhesiveness for filling the pre-supplied rubber into the kneading zone 8a with, for example, a heater or warm water. Further, in addition to the kneading zone 8a, it is preferable to preheat the conveyance zone located upstream thereof. A continuous kneader having such a temperature-adjustable barrel is known (see, for example, Patent Document 1), and conventionally used for cooling and holding at about 20 to 40 ° C. in final rubber kneading.

  In order to specifically show the configuration and effects of the present invention, final rubber kneading was actually performed, and the initial flow loss at the start of kneading was investigated. In final rubber kneading, SBR non-pro rubber is used as raw rubber, sulfur (powder) as vulcanizing agent and vulcanization accelerator CBS (chemical name: N-cyclohexyl-2-benzothiazole sulfene) as vulcanizing chemical. Amide) (powder). As shown in Table 1, the amount of rubber blended (phr) was 2.0 phr for sulfur and 1.5 phr for the vulcanization accelerator CBS relative to 165 phr for the SBR non-pro rubber.

Comparative Example 1
The rubber continuous kneading equipment having the configuration shown in FIG. 1 was used, and final rubber kneading was performed by supplying raw rubber from the start of kneading without performing the pre-feeding step. The raw rubber used was a non-pro rubber formed into a pulverized product having an average particle size of 5.4 mm by a pulverizer (using a 12 mm mesh screen) and coated with an anti-adhesive (calcium carbonate) (referred to as NP1). .

Comparative Example 2
The rubber continuous kneading equipment having the configuration shown in FIG. 1 was used, and final rubber kneading was performed by supplying raw rubber from the start of kneading without performing the pre-feeding step. The raw rubber used was a non-pro rubber formed into square pellets having an average particle size of 4.7 mm by a 5 mm square sheet pelletizer and coated with an anti-corrosion agent (calcium carbonate) (referred to as NP2).

Example 1
The rubber continuous kneading equipment having the configuration shown in FIG. 1 was used, and when starting kneading, the pre-supplied rubber was supplied prior to the raw rubber, and final rubber kneading was performed. As the raw rubber, the raw rubber of NP1 was used. In addition, as the pre-supplied rubber, an SBR polymer coated with an anti-corrosion agent (calcium carbonate) was used as a rough cut product having an average particle diameter of 10.7 mm by rough cutting into 10 to 12 mm square with a knife.

Example 2
The rubber continuous kneading equipment having the configuration shown in FIG. 1 was used, and when starting kneading, the pre-supplied rubber was supplied prior to the raw rubber, and final rubber kneading was performed. As the raw rubber, the raw rubber of NP1 was used. In addition, the pre-supplied rubber has the above-mentioned non-pro rubber, which has been lost behind in the past lot, as a rough cut product having an average particle diameter of 10.5 mm by rough cutting to 10 to 12 mm square with a knife, The one coated with calcium carbonate (referred to as NP3) was used.

Example 3
The rubber continuous kneading equipment having the configuration shown in FIG. 1 was used, and when starting kneading, the pre-supplied rubber was supplied prior to the raw rubber, and final rubber kneading was performed. As the raw rubber, the raw rubber of NP1 was used. The pre-supplied rubber was a non-pro rubber molded into square pellets having an average particle size of 9.5 mm (referred to as NP4) using a 10 mm square type sheet pelletizer.

Example 4
When the rubber continuous kneading equipment having the configuration shown in FIG. 2 was used and kneading was started, the pre-supplied rubber was supplied prior to the raw rubber to perform final rubber kneading. As the raw rubber, the raw rubber of NP2 was used. For pre-supplied rubber, the above non-pro rubber is formed into a pulverized product having an average particle size of 7.0 mm using a pulverizer (using a 15 mm mesh screen), and the small particle size rubber is removed using a sieve having an aperture of 6.7 mm. Then, it was immersed in a dilute acetic acid solution and stirred, and the anti-adhesive was removed by melting, washed with water and dried (referred to as NP5).

  In any of the above rubber kneading, as a continuous kneader, CUSPERION BUSS Kneader MKS-70 (screw L / D (length / shaft diameter): 8, barrel inner diameter D1: 70 mm, screw shaft diameter D2: 45 mm), the number of revolutions of the screw was 130 rpm, and the throughput was 100 kg / h. Moreover, the supply amount of the pre-supply rubber in Examples 1 to 4 was 70 g. The results are shown in Table 2.

  From Table 2, in Comparative Examples 1 and 2, the raw material discharge portion in which the powdery raw rubber is discharged as it is in the form of supply, and the kneading failure (physical property failure) in which the raw rubber is discharged in an insufficiently kneaded state It is confirmed that an initial loss of less than 4 kg occurred. On the other hand, in Example 1, there was no discharge of the original shape, and the amount of kneading of the pre-supplied rubber having a different composition from the raw rubber was lost as a physical property defect, and the initial flow loss was suppressed. You can see that Moreover, in Examples 2-4, it turns out that the original shape discharge | emission and the kneading | mixing failure have not generate | occur | produced by supplying pre-supply rubber | gum prior to raw material rubber | gum, and the initial flow loss is suppressed effectively. . In Example 4, although the particle sizes of the raw rubber and the pre-supplied rubber are relatively small, the effect obtained by removing the anti-adhesive agent is exerted, and the initial flow loss is suitably suppressed.

Schematic configuration diagram of a rubber continuous kneading facility according to the first embodiment AA step view in FIG. Schematic configuration diagram of rubber continuous kneading equipment according to the second embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous kneading machine 2 Barrel 4 Supply port 7 Shear pin 8 Kneading zone 8a Kneading zone located in the most upstream side 9 Conveyance zone 10 Screw 12 Screw blade 14 Kneading segment 15 Conveying segment 20 Rubber supply device 30 Chemical supply device D1 Barrel Inner diameter D2 Screw shaft diameter

Claims (4)

In a rubber continuous kneading method comprising a supply step of continuously supplying powdery raw rubber to a continuous kneader, and a kneading step of kneading the raw rubber in a kneading zone of the continuous kneader,
When starting kneading, before the supplying step, a pre-supplying step of supplying a predetermined amount of pre-supplied rubber having a particle size larger than the raw rubber to the continuous kneader,
The rubber continuous kneading method, wherein the kneading step is to feed and knead the raw rubber into the kneading zone filled with the pre-feed rubber.   The continuous kneader includes a cylindrical barrel having an inner diameter of D1, and a screw rotating around the axis within the barrel and having an axis diameter of D2, and the particle size d of the pre-feed rubber is (D1- The continuous rubber kneading method according to claim 1, wherein D2) /2×0.5≦d is satisfied.   The rubber continuation according to claim 1 or 2, wherein the pre-feed rubber is in a powder form and includes an anti-adhesive removing step for removing the anti-adhesive applied to the pre-feed rubber before the pre-feed step. Kneading method. Any one of Claims 1-3 provided with at least one of the rubber | gum preheating process which preheats the said pre-feed rubber before the said pre-feed process, and the kneading | mixing zone pre-heating process which preheats the said kneading | mixing zone until the said pre-feed rubber is filled. The rubber continuous kneading method according to claim 1.

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